Apparatus for producing cellular concrete



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July l2, 1938. J. A. RICE APPARATUS FOR PRODUCING CELLULAR CONCRETEFiled oct'. 18,- 19:55

2 Sheets-Sheet l Examiner I06. COMPOSITIONS,

I Cross Reference COATING OR PLASTIC.

July 12, 1938. J. A. RICE APPARATUS FOR PRODUCING CELLULAR CONCRETEFiled Oct. 18, 1935 2 Sheets-Sheet 2 Patented July 12, 1938 UNITEDSTATES PATENT OFFICE 2,123,804 APPARATUS FOR PRODUCING CELLULAR CONCRETEApplication October 18, 1935, Serial No. 45,684

'4Claims. (01M I)?? If/ The present invention relates to a method of andapparatus for producing cellular concrete and consists in the novelsteps of procedure, and

combinations and arrangements of elements of apparatus hereinafterdescribed and particularly set forth in the accompanying claims.

The disclosure herein forms a continuation in part of my co-pendingapplication for U. S. Patent I on Process and apparatus for makingacoustic 0 material and foaming compounds, filed April 27, 1931, SerialNo. 533,351, and of which parent application there is filed of even datea divisional application for patent on Acoustic material and process ofproducing the same, Serial No. 45,685,

filed October 18, 1935.

The method phase of the invention consists essentially in combining acement lurr with a suitable foaming com ound and then aeratin the ixtureBy mechanically beating oi"'1'fi'c'orporatwag Herein the films of air bymeans of foraminous or perforated sheets, e. g. screens, that enter thematerial carrying entrained air which thereafter forms into bubbles thatharden and produce a cellular product.

The apparatus is characterized in that it embodies a plurality ofarcuate or cylindrical-like sections of screen or perforated materialspirally arranged on a common rotatable shaft, which in operation serveto drag films of entrailing air into the mixture of slurry and foamingsolution, and simultaneously therewith agitate the mass to thoroughlydistribute the created bubbles thus obtaining a uniformally cellularstructure.

The invention is shown by way of illustration in the accompanyingdrawings wherein:

Figure 1 is a vertical sectional view of the machine,

Figure 2 a central sectional view thereof taken on the line 22 of Figurel.

Figure 3, a central sectional view showing a modified form in whichquarter spirals are used.

Figure 4, a similar view having one complete spiral.

Figure 5, an embodiment in which only a portion of a spiral is employed,and;

Figure 6, a further embodiment disclosing one continuous spiral of fourconvolutions.

Referring to the construction in further detail, the apparatus consistsof a series of arcuate or cylindrical shaped sections III, II, l2, I3,l4, l5, l6, and I1, formed of screen, w i re cloth expanded or punchedsheet metal or other similar material, arranged in spiral like form onthe rotary shaft l8, said shaft being journalled on bearings I9 and 20within a suitably shaped container 2| having discharge outlet 38. Thereare appreciably wide and open spaces, 22, 23, 24, 25, 26, 21,

28, and 29 between said screen members, and at .30, 3|, 32, 33, 34, 35,36, and 31 are stops or barriers, also made of the same or similarmaterial as the screen members. The cement and water, with or withoutaggregate forming a thin slurry, (usually in an auxiliary slurry mixer),are poured into the container 2!, approximately sufficient to fill thesame up to the level of the dotted line 10 f.f. Sufficient foam compoundis then introduced into the machine, and immediately becomes mixed withthe slurry giving the same a foamy character,--that is to say,making itto be of a foamy nature. 15

The screen members, after initially passing through the slurry, willbecome coated with numerous thin films, and thereafter when the spacesbetween the turns of the screens are submerged in the slurry, numerousair cells will 20 be formed by the discharge of entrapped air into theslurry through the meshes of the screens. Upon emergence from theslurry, the closed spaces between the screens will again become largelyfilled with air when the slurry flows out by 35 gravity, and theoperation will be repeated during each revolution of the shaft. Thespiral principle is believed the most suitable for handling slurries ofall kinds such as Portland cement,

clay all thick solutions, and mixtures 30 of liquids and solids in whichit is desired to incorporate a cellular structure by means of gasbubbles.

In the modified construction shown in Figure 3 there are four arcuatesections 39 disposed in 35 spiral relation providing spaces 4! betweenthe adjacent ends thereof through which the mixture enters. The screen42 in Figure 4 is in one piece forming a complete spiral having anopening 43 for the material. In Figure 5 the screen 44 is in 40 onepiece arranged spirally for approximately one-third the circumference ofthe disks 40, and its trailing end is spaced from the edge of disks 40to provide an entrance opening 45. The screen 46 in Figure 6 is in onepiece and of a length 45 to form four complete convolutions having anentrance opening 41 between its leading end and the adjacentconvolution.

The function of the barriers or stop members 3| to 31 is to impede theflow of slurry along 50 the spiral channels between the screen membersand to form closed spaces when the meshes are filled with films, thuscarrying the maximum volume of air deeply into the slurry and givingefficiency to the machine. The use of these stops 55 or barriersincrease the output of the machine to an extent appreciably greater thanif they were not used. The several sections IO-I'I are assembled in suchangular relation that the respective front or advancing edges thereofare uniformally located about the circumference of the tank, and thebarriers or bafiies 30-31 are similarly arranged, all to the end of evendistribution of load on the machine during working as will beunderstood. Continued operation of the machine as described will finallyuse up the available water of the slurry, forming air cells each with asurrounding film of water containing a minute quantity of foamingcompound. Thus the aeration will cease when no more water is available,and the slurry will cease to expand in volume as a consequence. If morewater is added and the machine operated, the slurry will furtherincrease in volume due to additional films being formed with airentrapped therein.

A suitable mixture is:

When aerated, this mixture will have a volume of approximately six cubicfeet, weighing approximately forty-five (45) pounds to the cubic foot.Mixtures of heavier or lighter weight to the cubic foot may be made bycorrespondingly decreasing .or increasing the amount of water used thusincreasing or decreasing the proportion of air cells in the batch.Different kinds of materials may obviously be used e. g. concrete,portland cement, gypsum, clay, or other cementitious subsances, and itis preferred to combine the cement slurry with the foaming compound andthen to aerate the mixture as explained.

By varying the character of the compound, the

of the invention except as defined by the claims.

What is claimed as new is:

1. An apparatus of the character described comprising a slurry mixturetank, a shaft journalled therein, a plurality of arcuate members offoraminous material mounted in angularly l5 spaced relation on saidshaft, and a plurality of radially disposed foraminous membersassociated with said arcuate members and cooperable therewith to dipinto the slurry mixture and emerge therefrom whereby to cause entrappingof air bubbles therein, as and for the purpose set forth.

2. In an aerating device as in claim 1 foraminous partitions arrangedacross the spiral-cylindrical members, and dividing the same into aplurality of compartments to increase the air en- 2 the same into aplurality of compartments to increase the air entrapping effect.

-4. An apparatus of the character describg comprising a slurry mixturetank, a shaft bow nailed therein, a plurality of spiral-like members offoraminous material mounted on the shaft in angularly spaced relation,and a plurality of foraminous members radially intersecting said arcuateforaminous members and cooperable therewith to dip into the slurrymixture and emerge therefrom whereby to cause entrapping of a) JOHN A.RICE.

